On hover over PR “Files changed” tab, show a popup with the list of files

On hover over the Files changed tab of the page for a pull request, show a popup with the list of files.

For example, when I hover of the Files changed tab of https://github.com/mdn/browser-compat-data/pull/6958, I get a popup showing:

mathml/elements/math.json
mathml/elements/mglyph.json
mathml/elements/mlabeledtr.json
mathml/elements/mo.json
mathml/elements/mspace.json
mathml/elements/mstyle.json
mathml/elements/mtable.json
mathml/elements/mtd.json
mathml/elements/mtr.json

Rationale: It’d be convenient if I didn’t need to actually open the https://github.com/mdn/browser-compat-data/pull/6958/files page just to see the list of which files got touched.

[fregante]

I think that in the past I would have liked to see the file list while leaving a comment, so I wouldn’t be opposed to such a feature as long as:

• it’s limited to ~10 files
• it’s loaded on hover
• it uses the title attribute (.tooltipped is clipped by the tabnav’s overflow:auto)

Example:

It probably isn’t a very difficult feature if the title attribute can be updated on the fly on every browser.

[fregante]

Saving your code in this commit: 0d8be65a26ee5c6005e5e5a8efdf5fc4b23761e2

But closing and deleting the branch